Hydraulic transmission and control for guns



Feb. 19, 1952 E. WIEDMANN HYDRAULIC TRANSMISSION AND CONTROL GUNS Filed Nov. 13, 1950 minnmOkOE mduw 20:05am- JNVENTOR. ER N S T WIEDMANN ATTORNEY Patented Feb. 19, 1952 assezso HYDRAULIC TRANSMISSION AND CONTROL FOR GUNS Ernst Wiedmann, Summit, Wis., assignor to The oilg ar mpany, Milwaukee, W a c p ration of Wisconsin Application November 13, 1950, Serial No. 195,381

6 Claims.

This invention relates to hydraulic transmissions of the type which includes a hydraulic motor adapted to move an element into and hold it in selected positions, a :variable displacement pump for supplying liquid to the motor to energize it and a control for regulating the displacement of the pump to thereby control the operation of the motor.

A transmission embodying the inventionis par.- ticularly adapted toform-a part of the elevating mechanism of guns, :suchas a gun carried by a military tank, and the inventionwill be explained asbeing employed for this purpose but it is to be understood that .the invention is notlimited to Such use.

To train such .a gun on a target, the elevation of the gun is changed until the target appears in the center of the field of vision of a telescope which is movable with the gun. The gun may be fired at .the target if the elevation of the gun is correct for the distance between the gunand the target but, if theelevation is incorrect for that distance, the elevation of the gun must be changed which necessitates changing the .angle between the telescope and the gun in .order that the gunner ,can see the target through the telescope.

The primary object of the present invention is to provide means whereby the elevation of .the gun can be changed without changing thelposiy tion of thetelescope.

A gun elevating mechanism embodying the invention has the advantage that -a,-gun may be adjusted into position for firing at a target in much less time than was required to adjust the prior gun elevating mechanism.

The invention is exemplified by thegun elevating mechanism shown schematicallylin .the ac.-

companying drawings.

For the purpose of illustration, the invention has beenshownlappliedto agun I the trunnions 2 of which arejournaled in a support 3 which maybe fixed to or formed integral with the turnet of "a tank ,not shown. w Gun l is adaptedto be tilted about the axis of trunnions 2 by a hydraulic motorehaving its cylinder 4 restrained from axial movement and its piston .5 fitted in cylinder 4 and connected ltogun l by a rod 6. As shown, cylinder .4 haswthe head end thereof pivotally connected by a pin 1 to (a bracket -8 whichv'may be .fixed to or formed integral ,with' the :tank turret, and vrod 6 is connected. by? lpin Stoaiug l fixed to the breech of .gun I.

{Zlhe arrangement is ,such that, when ,motive liquid is supplied to the head end of cylinder li,

it will force piston :5 rear-ward and cause rod 6 to exert upon pin!) a rearward and downward force the verticalcomponent of which will depress the breech of gun I and elevate the muzzle thereof. Pin 9 will move with gun I and cause cylinder 4 to pivot upon pin 1. When motive liquid is supplied to the rod end of cylinder 4, it will force piston 5 forward and cause rod 6 to exert upon pin 9 a forward and upward force the vertical component of which will raise the breech of gun I and thereby depress the muzzle thereof.

Liquid for energizing motor 45 is supplied by a reversible variable displacement pump 1 5 which is driven by an electric motor l6 and is connected to opposite-ends of cylinder 4lby ,two channels Hand I8. Motor Iii-operates continuously when use of gun I is anticipated. Pump l5 may be of any suitabletype but for the purpose of illustration it has been indicated as being somewhat similar to the pump-shown in Patent No. 2,406,138. It is deemed sufficient to .state that ':the pump shown includes'a control I9 having a shaft 20 extending therefrom and that rotation of shaft 20 in one directionorthe other will cause pump IE to discharge liquid in a directionaand at a rate dependent upon the direction and the angular distance shaft 20 is'rotated from its normal or neutral position in which position of shaft 2!! pump displacement zero.

v Control shaft-20 is mechanically connected to one leg '2! of a first difierential DI, a second leg 22 of which is connectedthrough reduction gear 23 to a small variable speed electric motor 24 which is controlled by a manually operable control 25. The arrangement is such that, when control 25 is adjusted in one direction .or the other, motor 24 will ,operate in one direction-or the otherand will rotate leg 22 of differential DI in one directionvor theotherand, if the third leg 26 of differential DI isstationary or is rotating at a slower speed, leg 2| willrotate shaft 20 in one direction or the ,other and thereby cause pump l 5-to deliverliguid tovoneend or the other of motor 4-e-l5.

The third leg .26 .of differential DI is connected to one leg 21 of a second differential D2 a second leg 28 of which is connected through .a reduction gear ,29 toan ele ctricallytoperated device 30 which has been designated a super elevation .receiver.

,Thecthird leg}! of diflferential D2 is connected to a drum 32 having one end of a wireor cable 33 fixed thereto. Cable 3,3 passes lover a plurality of deflector sheaves .34, itlias .its ether end fixed i rmoverpen W theun ha yb in fa tened t lug I0, and it is kept taut by sprin means such as a torsion spring 35 associated with drum 32. Cable 33, drum 32 and spring 35 constitute a feed-back for transmitting motion from gun I to pump control shaft 20 through differentials DI and D2.

The arrangement is such that, when the elevation of gun I is changed in response to operation of control 25 as explained above, cable 33 will cause drum 32 to rotate leg 3| of differential D2 or will permit spring 35 to rotate it, depending upon whether the muzzle of gun I is being elevated or depressed. Since leg 28 of differential D2 is normally held stationary by device 30 as will presently be explained, rotation of leg 3| causes leg 21 to rotate leg 26 of differential DI in a direction opposite to the direction of rotation of leg 22. The parts are so proportioned that leg 26 will rotate at the same speed as leg 22 so that further adjustment of pump I is stopped unless control 25 is further adjusted to cause motor 24 to effect a change in the speed of leg 22 which will immediately eifecta change in the speed of gun I and thereby immediately effect a change in the speed of leg 26. When control 25 is returned to its neutral position, rotation of leg 22 Will cease and leg 26 will rotate leg 2| far enough to cause pump control shaft to return to its neutral position. The several movements have been explained as occurring in sequence but actually gun I moves and stops substantially in synchronism with the movement of control from and to its neutral position.

Differentials DI and D2, electric motor 24 and device 30 have been shown spaced from each other and from pump I5 but in practice they are arranged in a compact assembly upon the casing of pump I5. Also, differentials DI and D2 have been shown as being of the bevel gear and pinion type, the first leg of differential DI has been shown as being connected to pump control shaft 20 by a bevel pinion 36 and a shaft 31 and the third leg 3| of differential D2 has been shown as being connected to drum 32 by a bevel pinion 38 and a shaft 39 but in practice differentials DI and D2 are of the spur gear and pinion type, the first leg of differential DI is geared directly to the pump control shaft and drum 32 is fastened directly to the third leg of differential D2.

Operation of device 30 is effected in response to adjustment of a range finder 40 to which device 30 is electrically connected, as indicated by the electric cable 4|, and which is provided with means, which have been represented by the knob 42, for adjusting it to determine the distance to the target. Range finder 40 is connected to gun I by means which normally holds it in a fixed relation to gun I so that, when gun I is rotated upon trunnions 2 through any angular distance in response to operation of control 25, range finder 40 is rotated through exactly the same angular distance. For the purpose of illustration, the means for connecting range finder 40 to gun I has been represented by a link 43 which connects it to pin 9 but the means used in practice is quite different.

No details of either device 30 or range finder 40 have been shown for the reason that each constitutes an independent invention. It is deemed sufficient to state that operating the adjusting means of the range finder establishes an electric circuit and also adjusts the connection between the range finder and the gun, that establishing an electric circuit will cause device 30 to operate and effect a change in elevation of the gun as will presently be explained, and that adjustment of the connection between the range finder and the gun will prevent any substantial movement of the range finder due to the elevation of the gun being changed in response to operation of device 30.

The arrangement is such that, after control 25 has been operated to change the elevation of the gun until the range finder is trained upon a target and control 25 has been returned to its neutral position to cause pump I5 to return to zero stroke and enable motor 4-5 to hold the gun and the range finder stationary, the range finder will indicate whether the target is within, beyond or short of the range of gun I at its present elevation. If the range finder indicates that the target is within range, the gun may be fired at the target.

If the range finder indicates that the target is beyond the present range of the gun, the range finder adjusting means (represented by knob 42) is turned in one direction until the range finder indicates the distance to the target. Turning knob 42 in that direction establishes an electric circuit which will cause device 30 to rotate leg 28 of differential D2 in a given direction. Since leg 3| is held stationary by feed-back 32--35 at the instant that leg 28 starts to rotate, rotation of leg 28 will cause leg 21 to rotate leg 26 of differential DI. Since at this time leg 22 of differential DI is held stationary by motor 24, rotation of leg 26 will cause leg 2| to rotate pump control shaft 20 in a direction to cause pump I5 to deliver liquid through channel I8 to the head end of cylinder 4 and enable piston 5 to depress the breech of gun I and thereby elevate the muzzle thereof.

Depressing the breech of gun I causes feed back 32-35 to rotate leg 3| of differential D2 in a direction and at a rate which counteracts the effect of rotation of leg 28. When rotation of knob 42 ceases rotation of leg 28 of differential D2 will cease and permit leg 3| to rotate leg 21 in the opposite direction which will cause differential DI to rotate shaft 20 in the opposite direction until the displacement of pump I5 has been re-' duced to zero, thereby stopping gun I and holding it in the position determined by the adjustment of range finder 40. The gun may then be fired at the target.

It should be noted at this point that device 35 does not rotate leg 28 of differential D2 througli an angular distance proportional to the angular distance through which adjusting knob 42 is rotated but it rotates leg 28 through an angular distance which is determined both by 'the angular distance through which knob 42 is rotated and the angle of the gun. The reason for this is that, when a gun is adjusted to fire at short range, a given increase in range may be obtained by raising the muzzle through a short distance, but when the gun is adjusted to fire at long range, the muzzle of the gun must be raised through a much greater distance to obtain the same increase in range.

Device 30 is not only a power device for rotating leg 28 of differential D2 but is also a calculating machine which, in response both to the angular distance through which knob 42 is rotated and also to the range in which rotation of knob 42 rotated to effect adjustment of gun I to such a position that a projectile fired by it will strike= t erase Depressing the breech of gun ldoes not change the elevation of range finder 4i! because'turning knob 42' in a direction to'elevate the-muzzle of gun I also causes a simultaneous and corresponding increase'in the length of the connection-ha tween range finder 40 and gun Lsuch as by lowering that part of the range finder to which link 43 is connected.

If after range finder All has been trained upon the target it indicates that the target is short of the range 'of gun l at the present elevation thereof, the range finder adjusting means is rotated a direction opposite to the direction in 'which it is turned to effect an elevation of the muzzle of gun I. Turningthe adjustingomeans in that direction shortens the-connection between range finder 40 and gun I and causes "the apparatus to function in the above described manner but in the opposite direction which causes pump I5 to deliverliquid to "the rod end of cylinder 4 and enables :piston5 to raise the breech of--gun 1 until adjustment of range finder 4B ceases'andthen the :gun may be fired at the target.

The operation of the apparatus has been explained as though the several movements occur in sequence but actually gun I starts to move at almost the same instant that adjustment of range finder 40 is started and adjustment of ranger finderdll can be started before operation of-control '25 is completed.

'A gun provided with the elevating mechanism embodying the present invention may thus be adjusted 'to the correct range more easily and inmuch less time than is possible with the prior gun elevating mechanisms.

While the invention has been explained as being embodied in a specific gun elevating mechanism, it is not limited to such use but may be modifiedlin various ways and adapted to other uses without-departing from the scope-of the invention which is hereby claimed as follows:

1. An elevating mechanism for a-gun, comprising a' hydraulic motor connected to said gun and adapted when energized to change the elevation of said gun, a pump hydraulically connected to said motor for supplying liquid thereto to energize the same-and having means for varying its displacement, a feed back from said gun for creating motion "in'responseto a change in the elevation of said gun, a range finder normally movable with said gun and independently adjustable to vary the angle between it and said gun, a device for creating motion in response to said range finder being adjusted, a first three legged differential having a first leg thereof connected to said pump displacement varying means to operate the same, means for rotating a second leg of said difierential to thereby cause the first leg thereof to effect adjustment of said pump displacement varying means in response to relative rotation of the second and third legs of said differential, and a second three legged differential having a first leg thereof connected to said feed back, a second leg thereof connected to said device and the third leg thereof connected to the third leg of said first differential so that operation of said feed back in response to a change in the elevation of said gun or operation of said device in response to adjustment of said range finder will cause said second differential to rotate the third leg of said first differential and thereby modify the effect of the rotation of the second legof said first differential.

2. An elevating mechanism for a gun, comprising a hydraulic motor connected to said gun and '6 adapted when energized 'to change the elevation of 1 said gun, a. pump hydraulically connected to said motor for supplying liquid thereto to .energize the same and having means for varying its displacement, a feedback from said gun for creating motion in responseuto a change in the .elevation of said-gun, a range finder normally movable with said gun and independently adjustable to vary' the angle between it and said gun, a device for creating motion in response to said range finder being adjusted, a first three legged differential having-a first leg thereof connected to said pump displacement varying-means to operate the same, a variable speed electric motor for rotating-a second leg. of said differential to thereby cause the' first leg thereof to effect adjustment of said pump displacement varying means in response to relative rotation of the second and third legs of said differential, manually operated means for controlling said-electric motor, and a second three legged differential having a first leg-thereof connected to said feed back, asecond leg thereof connected to said device and the third leg-thereof connected to the third leg of said firstdifierential so that operation of said feed back i-nresponse to a change in the elevation of said gun or operation of said device in response to adjustment of said range finder will cause said second differential to rotate the third leg vof said firstrdifferential and thereby modify the effect of therotation of the second leg of saidifirst differential.

3. In an apparatus comprising a first element movable through a :predetermined'range, a second element movable with said first element and adjustable to change its position relatively to said vfirst element, a device for creating motion in response to said second element being adjusted, a hydraulic motor connected to said first element and adapted when'energized to move the same, anda .pump'hydraulically connected to said motor for supplying liquid thereto to energize the same andihaving means for varying its displacement, the-combinationof a first three legged differential having a first leg thereof connected to said pump displacement varying meansto operate the same, meansforarotating a second leg of said differential, avsecond three legged differential having'a first leg :rthereof 'connectedto the third leg of said first differential and a second leg thereof connected to said device, and means for rotating the third leg of said second differential in response to movement of said first element so that rotation of the second leg of said first differential relatively to the third leg thereof causes the first leg thereof to adjust said pump displacement varying means and movement of said first element or adjustment of said second element causes said second differential to rotate the third leg of said first differential and thereby modify the effect of rotation of the second leg of said first differential.

4. In an apparatus comprising a first element movable through a predetermined range, a second element movable with said first element and adjustable to change its position relatively to said first element, a device for creating motion in response to said second element being adjusted, a hydraulic motor connected to said first element and adapted when energized to move the same, and a pump hydraulically connected to said motor for supplying liquid thereto to energize the same and having means for varying its displacement, the combination of a first three legged differential having a first leg thereof connected to said pump displacement varying means to operate the same, a variable speed electric motor for rotating a second leg of said differential, manually operated means for controlling said electric motor, a second three legged difierential having a first leg thereof connected to the third leg of said first difierential and a second leg thereof connected to said device, and means for rotating the third leg of said second differential in response to movement of said first element so that rotation of the second leg of said first differential relatively to the third leg thereof causes the first leg thereof to adjust said pump displacement varying means and movement of said first element or adjustment of said second element causes said second differential to rotate the third leg of said first difierential and thereby modify the effect of the rotation of the second leg of said-first differential.

5. In an apparatus having a first element which is movable in opposite directions, a hydraulic motor connected to said element and adapted when energized to move said element in opposite directions within a predetermined range, a second element normally movable with said first element and adjustable in one direction or the other relatively to said first element, a first shaft, and a device operable in response to adjustment of said second element in one direction or the other.

for rotating said shaft in one direction or the other, the combination of a pump hydraulically connected to said motor and provided with displacement varying means for causing said pump to discharge liquid at variable rates in one direction or the other to thereby cause said motor to move said first element at variable rates in one direction or the other, a first three legged differential having a first leg thereof connected to said pump displacement varying means to operate the same, means for rotating a second leg of said differential, a second three legged differential having a first leg thereof connected to the third leg of said first diiferential and a second leg thereof connected to said shaft, and means for rotating the third leg of said second differential in one direction or the other in response to movement of said first element in one direction or the other so that rotation of the second leg of said first differential relatively to the third leg thereof causes the first leg thereof to adjust said ump displacement varying means and movement of said first element or adjustment of said second element causes said second differential to rotate the third leg of said first differential and thereby modify the effect of the rotation of the second leg of said first differential.

6. In an apparatus having a first element which is movable in opposite directions, a hydraulic motor connected to said element and adapted when energized to move said element in opposite directions within a predetermined range, a second element normally movable with said first element and adjustable in one direction or the other relatively to said first element, a first shaft, and a device operable in response to adjustment of said second element in one direction or the other for rotating said shaft in one direction or the other, the combination of a pump hydraulically connected to said motor and provided with displacement varying means for causing said pump to discharge liquid at variable rates in one direction or the other to thereby cause said motor to move said first element at variable rates in one direction or the other, a first three legged differential having a first leg thereof connected to said pump displacement varying means to operate the same, a variable speed electric motor for rotating a second leg of said differential, manually operated means for controlling said electric motor, a second three legged differential having a first leg thereof connected to the third leg of said first differential and a second leg thereof connected to said shaft, and means for rotating the third leg of said second difierential in one direction or the other in response to movement of said first element in one direction or the other so that rotation of the second leg of said first differential relatively to the third leg thereof causes the first leg thereof to adjust said pump displacement varying means and movement of said first element or adjustment of said second element causes said second differential to rotate the third leg of said first differential and thereby modify the effect of the rotation of the second leg of said first differential.

ERNST WIEDMANN.

No references cited. 

